patch 8.1.1721: build failure with normal features without netbeans interface

Problem:    Build failure with normal features without netbeans interface.
Solution:   Enable signs when using the text properties feature.

Author: brammool

src/feature.h

@@ -1236,7 +1236,7 @@
  * +signs		Allow signs to be displayed to the left of text lines.
  *			Adds the ":sign" command.
  */
-#if defined(FEAT_BIG) || defined(FEAT_NETBEANS_INTG)
+#if defined(FEAT_BIG) || defined(FEAT_NETBEANS_INTG) || defined(FEAT_TEXT_PROP)
 # define FEAT_SIGNS
 # if ((defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA)) \
 		&& defined(HAVE_X11_XPM_H)) \

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1721,
 /**/
     1720,
 /**/